Yeah i got an 06 TJ and i keep hearing this weird noise when im sitting at idle. First off what should the 4.0L idle at cuz to me its pretty low but i dont know im used to my diesel truck idling high.

Anyway, at idle i here this weird rattling kind of sound. It sounds like its coming from underneath the jeep where the driver sits. Strange thing is when i push the clutch in the noise goes away and soon as i let off the clutch the noise comes back...any ideas??? sounds like it is coming from around the trans somewhere

I noticed the same problem a week or two ago, and it's just a fact of life with TJ's with the 3550 transmission...the shafts turning with nothing to do (so to speak) make a lot of noise. Some do it worse than others. Two factors that make it worse are heat, and older tranny fluid (in my experience). I replaced the old fluid with some new Syncromesh and it quieted the rattles by about half. When you push in the clutch, the noise goes away...

With the newer 6-speed, I can't say. I don't know if it's known to have the same noises, or not.

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Thanks alot. I have crawled under and checked it a few days ago and before i checked it i thought it was the cat but like sundowner and the other person says its coming from the transmission and i guess thats normal?

It's normal for the NV3550. I'm not sure about the 6-speeds, although I did some quick searching on the matter and discovered that it can make similar noises for a variety of reasons. I'd suggest you start your investigation under that premise.

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I have an '06 with the NSG370 6 speed and Dana 44 rear and Dana 30 front like you. I bought the Jeep new from the dealer and have had this issue since the day I drove it off the lot. My jeep has just over 60K on it and the rattle has never gotten worse. I have always done the normal preventative maintenance on time as well. I always thought it sounded like rattling coming from the clutch pedal linkage. It tends to diminish/go away when I put a small amount of pressure on the clutch pedal or if I push in the clutch pedal all the way. That is what I attributed it to. Never seemed to cause any problems for me. I did have a problem with the cluctch relay switch that prevented the Jeep from starting, but that was replaced under warranty.

HMM, i have a 2006 TJ, Dana 44 rear, 30 front, 6spd transmission and i JUST noticed a weird rattle sound, and after getting under the jeep, it sounds like it is coming from the transmission. almost right where it meets the engine. If you guys are still monitoring this post, is this about what you guys are hearing as well? like i said, never heard it before, and, like my name says, drive my jeep naked as much as possible. its loud right when i start it, and gets a little quieter after its driven. seems to go away when the rpms are higher, but it the noise could be drowned out by the engine noise. its actually kind of annoying. anyway, if anybody on this thread that has similar problems, just confirm that it hasnt gotten worse, and that its coming from roughly the front of the transmission near the engine. THANKS! AND JEEPNAKED!

Hi i have a 2005 6 speed manual tj and i bought it used, anyway also when i idle it makes that rattle noise in the transmission, once i put the clutch in it goes away then let out it comes back. I had someone listen to it they said it sounded like the throughout bearing. idk just thought i'd put mine in as well.